158—ENGINE
CHRYSLER SERVICE MANUAL
cup seals on intake valve stems and over valve
guides (Figs. 20 and 21), and install valve
springs and retainers. Compress valve springs
with Tool C-3422. Install locks and release tool.
NOTE
If valves and/or seats are reground, check the
installed height of springs. Make sure measure-
ment is taken from full depth of counterbore
in cylinder head to top surface of spring re-
tainer. (If spacers are installed measure from
top of spacer). If height is 1 23/32 inches or
greater, install a 1/16 inch spacer (Part No.
1400482) in head counterbore to bring spring
height back to normal 1 5/8 to 1 11/16 in.
15.
HYDRAULIC TAPPETS
a. Preliminary to Checking Hydraulic Tappets
Before disassembling any part of engine to
check for tappet noise, check oil pressure at
gauge and oil level in oil pan. The pressure
should be between 40 to 65 pounds at 2,000
r.p.m. The oil level in pan should never be
above "full" mark on dip stick, nor below "add
oil" mark. Either of two conditions could be
responsible for noisy tappets.
Oil Level Too High—If oil level is above "full
mark on dip stick, it is possible the connecting
rods can dip into oil when engine is running
and create foaming. This foam is fed to the
hydraulic tappets by the oil pump, causing
them to go flat and allowing valves to seat
noisily.
Oil Level Too Low—Low oil level may allow
pump to take in air which, when fed to tap-
pets,
causes them to lose length and allows
valves to seat noisily. Any leaks on intake side
of pump through which air can be drawn will
create the same tappet action. When tappet
noise is due to aeration, it may be intermittent
or constant, and usually more than one tappet
will be noisy. When oil level and leaks have
been corrected, the engine should be run at
fast idle for sufficient time to allow all of the
air inside of tappets to be worked out.
b.
Tappet Noises
To determine source of tappet noise run en-
gine at idle with cylinder head covers removed.
Feel each rocker arm to detect the noisy tap-
pet.
NOTE
Worn valve guides or cocked springs are some-
times mistaken for noisy tappets. If such is the
case, noise, in all probability, will be dampened
by applying side thrust on valve spring. If noise
is not appreciably reduced, it can then be as-
sumed the noise is in the tappet.
Valve tappet noise can be separated into two
types,
light noise and heavy noise. A light noise
is usually caused by excessive leakdown around
the unit plunger, or by plunger partially stick-
ing in cylinder. A heavy noise is caused either
by a valve not seating, or by foreign particles
becoming wedged between plunger and tappet
body, causing plunger to stick in down position.
This heavy noise will be further evidenced by
clearance between valve stem and rocker arm
as valve closes. A tappet causing light noise can
be determined by pushing down on push rod
end of rocker arm. The noise will become more
audible and, if push rod end of rocker arm is
held down long enough, the intensity of noise
may increase. In either instance, the unit as-
sembly should be removed for further inspec-
tion and cleaning.
c. Removal of Tappets
(with Rocker Arms in Position)
NOTE
If all of tappets are to be removed, it will be
TOOL G3024
51x993
Fig.
22—Compressing Valve Spring (FirePower)
(Typical of SpitFire)
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